Means for producing axonometric drawing projections



Feb. 19, 1963 A. E. MOCULLOUGH 3,077,667

MEANS FOR PRODUCING AXONOMETRIC DRAWING PROJECTIONS Filed Aug. 10, 1959 United States Patent Ofitice 3,077,667 Patented Feb. 19, 1963 3,077,667 MEANS FOR PRODUClNG AXONOMETRIC DRAWING PROJECTIGNS Arthur E. McCuilough, Lee County, Keokuk, Iowa Filed Aug. 10, 1959, Ser. No. 832,598 2 Claims. (CI. 33-75) This invention relates to drafting means and more particularly to drafting equipment used for producing axonomeric projections from conventional orthographic views and vice versa.

There are many instances in the making of drawings wherein it is highly desirable to have at least one perspective view of the item being drawn. This is particularly true of mechanical drawings but well may be the case of many other types of drawings, even including Patent Ofiice drawings. While it is usually quite easy to produce plan views, such as the side view and end view of an object, it is difficult to visualize and execute axonometric drawings merely from the data of the side and end views. Obviously, the making of an isometric projection from conventional orthographic views becomes quite involved and time-consuming inasmuch as the desired perspective view cannot be projected directly from the orthographic views. However, in recent times some progress has been made in attempting to produce an axonometric projection directly from two or more orthographic views. This latter phase, however, is most involved and requires a complicated plotting machine and the use of many reference points and lines. Such a procedure cannot be accomplished by present drawing instruments.

Therefore, the principal object of my invention is to provide simple drafting tools that are capable of producing axonometric projections directly from two or more conventional orthographic views or, if desired, capable of producing conventional orthographic drawings directly from anisometric showing.

More specifically, the object of my invention is to provide a triangle drafting board for use in conjunction with a T-square having a head extending radially therefrom but at an angle to the longitudinal axis of the T- square.

Still further objects of my invention are to provide a means for producing axonometric drawing projections that is economical in manufacture, durable in use, and refined in appearance.

These and other objects will be apparent to those skilled in the art.

My invention consists in the construction, arrangements, and combination, of the various parts of the device, whereby the objects contemplated are attained as hereinafter more fully set forth, specifically pointed out in my claims, and illustrated in the accompanying drawings, in which:

FIG. 1 is a perspective view of my device in use,

FIG. 2 is an enlarged plan view of my means and illustrates the manner in which it is used,

FIG. 3 is an enlarged cross sectional view of the head portion of my T-square taken on line 33 of FIG. 2, and

FIG. 4 is a reduced plan bottom view of my T-square.

As herebefore indicated, it is necessary that I employ a unique drawing board or at least one that differs from the usual rectangular structure. In the drawing 1 show an equal angle triangle board designated by the numeral 16 and having, therefore, the three straight edges designated by the numerals 11, 12 and 13. I recommend that the drafting board be of this structure although it is possible to produce a perspective view by the use of a drafting board having only two straight lines extending from a corner angle that is a corner of an equal triangle.

However, in FIG. 2 of the drawing, 1 show the use of all three sides of the equal triangle drafting board 10.

I will next describe my T-square which is particularly adapted for use with my triangle drafting board. The numeral 15 designates the head of the T-sq-uare and which is substantially diamond-shaped, as shown in FIG. 4. This diamond-shaped head has four straight edges designated by the numerals 16, 17, 18 and 19. Extending transversely across the center area of the head 15 is a dovetailed groove 28. The numeral 21 designates the ruler or shaft portion of my T-square and which is slidably adjustably positioned within the dovetailed groove 20, as shown in FIG. 3. The numeral 22 designates one or more threaded posts on top of the head 15 for receiving a threaded nut 23. By this construction, when the nut 23 is in loosened condition, the ruler portion of the T- square may be slid in either direction for purposes of adjustment in the groove 20. After the desired position of the ruler portion is obtained within the groove of the head portion, the nut 23 is tightened for rigidly locking the ruler portion to the head portion. The straight edges 16, and 17, extend in opposite directions from the ruler portion of the T-square and each extends in the position of the head 15 in FIG. 4 at an angle of one hundred five degrees to the longitudinal axis of the ruler portion as measured toward the drawing end of the ruler portion 21. The straight lines 18, and 19, of the head 15 also extend at an angle to the longitudinal axis of the ruler portion and the angle of each of these latter straight edges is sixty (60) degrees with the position of the head 15 as depicted in FIG. 4. In projecting an axonometric projection from two or more plan views, the plan views are first produced on the drafting board, and in FIG. 2 I show three such drawings, i.e., the plan top view 25, the plan side view 26, and a plan end view 27. By merely using my triangular drafting board and T-square, the perspective or axonometric projection 30 is produced directly and easily from the previously prepared plan views 25, 26 and 27 as shown in FIG. 2. It will be noted that this axonometric View is produced merely by showing the proper straight edge of a head of the T-square on the proper side of the triangular drafting board. By reversing the process, it is as easy to produce the plan views 25, 26 and 27 from the perspective view 30 provided the perspective view is the first one produced on the drafting board.

Thus, it will be seen that I have overcome many difficulties herebefore encountered in drafting, and the same has been accomplished by a different type head slidably movable on the ruler blade and with the blade and head used in conjunction with a triangular-shaped drafting board. The T-square head is constructed, as before brought out, with two different sets of angles arranged in such a way that when placed against an angular-shaped board edge, it is possible to draw angle views of objects. By the use of my means, it is not necessary to employ the conventional thirty (30), sixty (60), or forty-five (45) degree triangles. My device quickly shows the relationship of the various orthographic views of the object being drawn and does not require the additional handling of triangles, reference points, reference lines, and like. Furthermore, by the use of my means for producing drawings, there is little chance of making errors when producing the perspective view or when making plan views from an existing axonometric showing. Also, for such reasons, my device is excellent in instructing draftsmen inasmuch as they can visually see exactly what is being done.

In the drawings I have illustrated simple drawings and projections but my device is excellent in the construction of an isometric drawing having circles, arcs, or curves,

since by direct projection of common points on the various orthographic views, several intersecting points can be easily located on the isometric drawing and the curved surface drawn in its correct perspective and location. Likewise, having any point or position located in the orthographic views, it is a simple matter to select such a pointer position in the isometric showing by extending the projection of the point until it intersects in the isometric view.

Some changes may be made in the construction and arrangement of my means for producing axonometric drawing projections without departing from the real spirit and purpose of my invention, and it is my intention to cover by my claims, any modified forms of structure or use of mechanical equivalents which may be reasonably included within their scope.

I claim:

1. In combination for the selective practice of axonometric and isometric projection, a drafting board having at least three straight sides and on a face of which a drawing having either orthographic views or an isometric viewmay be placed, with at least one coordinate for either of said views placed parallel to at least one side of, said board, and a T-square for use with said drafting board, said T-square having a diamond-shaped head in plan view slidably mounted on a ruler portion of said T- square and adapted for securement to either end of said ruler portion, said head in one position on said ruler portion having a pair of edges on one side thereofextended away from each other each at an identical angle from the longitudinal axis of said ruler portion as measured toward said ruler portion, and said head having. another pair of edges on the opposite side thereof extended away from each other at an identical smaller angle from the longitudinal axis of said ruler portion as measured. toward said ruler portion, said T-square head adapted to be selectively placed with either one of said edges fiat against one of said board sides whereby said ruler portion is usable for axonometric projection along at least onecoordinate from orthographic views or for isometric projection along at least one coordinate from an isometric view, and said T-square adapted after movement of said head to the other end of said ruler to be placed with either of said another pair of-edges flat against one of said, board-sides whereby said ruler portion is usable for interconnectingv at right angles orthographic view lines. projected from an isometric view.

2. In combination for the selective practice of axonometric and isometric projection, a three-sided drafting board having equilateral straight sides and on a face of which a drawing having either orthographic views or an isometric view may be placed, with at least one coordihate for either of said views placed parallel to at least one side of said board, and a T-square for use With said drafting board, said T-square having a diamond-shaped head in plan view slidably mounted on a ruler portion of said T-square and adapted for securement to either end of said ruler portion, said head in one position on said ruler portion having a pair of edges on one side thereof extended away from each other at a 105-degree angle from the longitudinal axis of said ruler portion as measured toward said ruler portion, and said head having another pair of edges on the opposite side thereof extended away from each other at a -degree angle from the longitudinal axis of said ruler portion as measured toward said ruler portion, said T-square head adapted to be selectively placed with either one of said edges flat against one of said board sides whereby said ruler portion is usable to project along one coordinate from one view toward one view to be produced, said T-square head placeable with either one of said edges flat against other ones of said sides whereby all three coordinates may be projected, and said T-square adapted after reversal of said head to be selectively placed against any one of said sides whereby said ruler portion is usable for interconnecting at right angles orthographic view lines projected from an isometric view.

References Cited in the file of thispatent UNITED STATES PATENTS 490,893 Austin Ian. 31, 1893' 2,412,194 Anderson Dec. 10, 1946 2,717,817 Reichman .i Sept. 13, 1955- FOREIGN PATENTS 9,320 Great Britain 1909 605,506 France Feb. 19, 1926 633,172 Germany July 21, 1936 OTHER REFERENCES Technical Drawing FE Giesecke et 211., page 293, The MacMilland Company, New York, 1949. 

1. IN COMBINATION FOR THE SELECTIVE PRACTICE OF AXONOMETRIC AND ISOMETRIC PROJECTION, A DRAFTING BOARD HAVING AT LEAST THREE STRAIGHT SIDES AND ON A FACE OF WHICH A DRAWING HAVING EITHER ORTHOGRAPHIC VIEWS OR AN ISOMETRIC VIEW MAY BE PLACED, WITH AT LEAST ONE COORDINATE FOR EITHER OF SAID VIEWS PLACED PARALLEL TO AT LEAST ONE SIDE OF SAID BOARD, AND A T-SQUARE FOR USE WITH SAID DRAFTING BOARD, SAID T-SQUARE HAVING A DIAMOND-SHAPED HEAD IN PLAN VIEW SLIDABLY MOUNTED ON A RULER PORTION OF SAID TSQUARE AND ADAPTED FOR SECUREMENT TO EITHER END OF SAID RULER PORTION, SAID HEAD IN ONE POSITION ON SAID RULER PORTION HAVING A PAIR OF EDGES ON ONE SIDE THEREOF EXTENDED AWAY FROM EACH OTHER EACH AT AN IDENTICAL ANGLE FROM THE LONGITUDINAL AXIS OF SAID RULER PORTION AS MEASURED TOWARD SAID RULER PORTION, AND SAID HEAD HAVING ANOTHER PAIR OF EDGES ON THE OPPOSITE SIDE THEREOF EXTENDED AWAY FROM EACH OTHER AT AN IDENTICAL SMALLER ANGLE FROM THE LONGITUDINAL AXIS OF SAID RULER PORTION AS MEASURED TOWARD SAID RULER PORTION, SAID T-SQUARE HEAD ADAPTED TO BE SELECTIVELY PLACED WITH EITHER ONE OF SAID EDGES FLAT AGAINST ONE OF SAID BOARD SIDES WHEREBY SAID RULER PORTION IS USABLE FOR AXONOMETRIC PROJECTION ALONG AT LEAST ONE COORDINATE FROM ORTHOGRAPHIC VIEWS OR FOR ISOMETRIC PROJECTION ALONG AT LEAST ONE COORDINATE FROM AN ISOMETRIC VIEW, AND SAID T-SQUARE ADAPTED AFTER MOVEMENT OF SAID HEAD TO THE OTHER END OF SAID RULER TO BE PLACED WITH EITHER OF SAID ANOTHER PAIR OF EDGES FLAT AGAINST ONE OF SAID BOARD-SIDES WHEREBY SAID RULER PORTION IS USABLE FOR INTERCONNECTING AT RIGHT ANGLES ORTHOGRAPHIC VIEW LINES PROJECTED FROM AN ISOMETRIC VIEW. 